Pitch measurement method 1.
Roof framing measurements.
Slope the slope of a roof is represented as x 12 where x is the number of inches in rise for every 12 inches of run.
Roof framing rafter layout.
How to calculate your roof square footage first measure the length and width of each surface on the roof then multiply these values to get the square footage of that surface.
If this distance measures 4 inches you have a 4 in 12 pitch.
This will the first point of the rafter measurement line.
From one end of the rafter material using a speed square or framing square mark an x in 12 angle on the rafter and cut it.
Make sure to document the number of chimneys skylights or other obstructions and include dormers in your measurements.
This is very useful information for many purposes especially for roof framing the slope sometimes called pitch is calibrated on speed squares.
We ll use satellite imagery and trigonometry to calculate your roof s measurements.
8 inches and you have an 8 in 12 pitch.